Shaft-treating apparatus



H. O. LANG ET AL SHAFT TREATI NG APPARATUS Filed May 2, 1924 5Sheets-Sheet 1 Jan. 1, 19.29.

I y H. O. LANG l ET AL.

SHAFT TREATING APPARATUS 5 Sheets-Sheet 2 Filed May 2, 1924 afm Jan. 4I,1929.

H. O. LANG ET AL.

SHAFT TREATING APPARATUS Filed May 2, 1924 5 Sheets-Sheet 5 Jan. iI',l1929.

H. o. 4LANG ET Al. SHAFT TREAT-ING APPARATUS Filed May 2, 1924 5sheets-sheet 4 A Patented Jan. 1, lazaf --11u1\u'r1:u STATES PMENTAOFFICE..

HARRY 0. LANG AND JYOHN MOGEORGE, PONTIAC, MICHIGAN, ASSIGNOBS '.lO GEN-are provided with charging and discharging- RRAL MOTORS CoRIORATIo1\1,O1s` WARE.

Application filed May 2,

including shaft han ling devices which are controlled by anOperator,'but which can handle the,

shafts when they are at a temperature too high lfor easy manualhandling. In one desirable arrangement, 'a hardening furnace.

a quenching` tank, and a drawing furnace openings arranged substantiallyon -the circurference of a c1rcle,l and a circularly-movableoperator-controlled conveyor is arranged for transferring the shafts ina `vertical position successively to positions vertically above theopenings'of the hardening furnace, the quenching tank` and the drawingfurnace. In the embodiment shownA in the drawings, this conveyorincludes novel power-operated tongs for grasping and rais-` ing andlowering the shafts, Iandffor centering the shafts. t

vAnother feature of the invention lrelates A to an improved electricalfurnace especially l further advantage of adapted for use wtihapparatussuch as described above and which includes concentric series ofresistance elements between which vthe shafts are slowly moved by aturret or movable hearth, which supports them in a vertical position.-The shafts may be inserted into and removed from the furnace throughopenings vertically above shaft-supporting devices on the turret whenthe turret is at rest. By this arrangement the shafts are efficientlyheated by resistance elements which'are quite close to-them and there isno tendency for warping since the shafts are held in a verticalposition. A this construction is that the resistance elements and theshafts supported on the turretv may be almost com- Preferably, this isaccomtion, and partly DETROIT, MICHIGAN, A CORPORATION OF DELA-ysHAFT-TRRATING APARATUs.

1924. serial no. 716,685.

pletely enclosed with refractory material so that there is practicallyno loss of heat.

he quenching tank may also be provided, if desired, with a turret forsupporting the shafts while they are carried around from a chargingposition to a dischargingv position, and various features of theinvention relate to the novel construction of this quenching tank toprovide eiicient cooling of the shafts by' constantly circulated waterwhich is maintained at a uniform temperature, and especially toanarrangement for giving the water a helical or whirling mo'- tion, toinsure a uniform cooling action.

The above and other objects and features of the invention, includingvarious novel combinations of parts and desirable articularconstructions, will be apparent om the following description of theillustrative embodiment shown in the accompanying drawings, in which: Y

Figure 1 is a top plan view showing thel two furances and the quenchingtank, together with the conveyor;

Figure 2 isa view partly in side elevain vertical section, on the line 22 of Figure 1, and looking from the left in Figure 1;

Figure 3 is an end elevation, partly broken away, looking from thebottom of the sheet upwardly in Figure 1 and showing the relation of thedrawing furnace lto the' conveyor;

Figure 4 isa wiring diagram showing the stopping and starting controlfor one of the, furnaces;

Figure 5 is a vertical section through one of the tongs orshaft-carrying devices as it is grasping an untreated shaft;

Figure 6 is a side elevation of the top of the tongs, on a larger scalethanFigure 5;

Figure 7 is a vertical section on the line of Figure 1 showing theyquenching tank; and

Figure 8 is a vertical section through the driving. mechanism for thequenching tank with the central shaft in alinement with the part of thesame shaft shown in Figure 7, but looking in the opposite directionfromV Figure 7, tion from the arrows 7-7 in Figure 1.

The invention is shown in these drawings embodied in an apparatusincluding geni. e. looking in thel opposite direcv be stated that'thelegs 34 support erally a hardening furnace 10` electrically heated tofrom 1480o to 1525 F., a drawing furnace 12 which is exactly like thehardening furnace 10 except that it is only heated to a temperature ofonly 890 to 1000 F., a quenching tank 14 containing water automaticallykept at a temperature of'about 190 F. and a rotary conveyor 16for'placing the shafts successivelyin the hardening furnace, thequenching tank, andthe drawing furnace. The apparatus is shown asoccupying two iioors of a building, extending from the floor 18 of thebasement of the building to the ceiling 20 of the first floor so thatthe furnaces 10 and 12 and the quenching tank' 14 extend just above theintermediate floor 22. .f Just below the conveyor 16 is a circularplatform 24 for the operator or operators. Figures 1, 2, and 3, are onapproximately the same scale and in order to giveV a general idea of thesize of the variousparts it may distancefrom the platform 24 to thelower cross piece 26 (Figure 3) of the conveyor 16 is approximately 7feet. It is intended that one operator, or an operator at each end ofthe conveyor 16, as may be desired, will walk round and round on theplatform 24 as the conveyor transfers the shafts from one position -toanother as it turns.

The hardening ami drawing yfz/.rmwea-d The hardening furnace 10 and thedrawing furnace 12 may be, and arel shown as being, identical exceptthat the one is turned around 180 with respect to the other and exceptthat the hardening furnace is maintained at ahigher temperature than thedrawing furf nace. Each of these furnaces comprises a stationary casing30 of refractory material, such as fire brick or the like sheathedinsheet steel, supported from the'floor 18 of the basement on acentralcolumn ,32 shown as, bein ofrefractory material enclosed in ametal slieathing and on a plurality of legs 34 shown as being made ofmetal sheathed in cement. The column 32 supports the central column-likepart of casing 30, while the the outer annular wall. Each of thefurnaces is arranged to provide an annular open space 36 betweenconcentric series of resistance elements 38 and 40. Current is suppliedto thel resistance 'elements 38 by'conductors ance elements 40 byconductors 44. suitable automatic heat registering and recording device,including a pyrometer and a circuit controlled thereby, may if desiredbe provided for-keeping track of the temperature in the furnace; and itis also convenient to provide automatic means of well known characterfor controlling elements 38 and 4Q to give asubstantially'uniformtemperature. D i

The bottom of the annular o en space 36 in each furnace, is partially cled, by rings .vice 74 shown on a 42 and to the resst,

46 lof refractory `material which leave a central circular opening inranged an upwardly projecting annular portion 48 of a turret or vmovablehearth 50 supported on ball bearings 52 on a trac 54 carried by thecentral column 32. 1` To .prevent the escape of heated air from thespace 36 inthe 'furnace the metal bottomof which is arthe furnace isprovided with flanges 56 projecting int-o sand in annular pockets 58carried by the turret as' shown in Figure 2 in such a manner as to sealthe open space. Each track 54 isk clamped to its column 32 by clampscrews 55. By looseningl the screws, the track 54, and with it theturret50, maybe lowered to the bottom of column 32,` thus affording easyaccess to the annular chamber 36, and to the parts ofthe turret 50. lfdesired, filling tubes for adding sand may open through the top of thefurnace, and empty just above each of the annular pockets 58 vof theturret. Each of the turrets 50 is formed with a bevel ring gear 60 onits bottom driven by a bevel pinion 62 operated by reduction gearing 64from a shaft carrying a worm wheel 66 driven by a worm 68 on thearmature shaft ofl a motor 70, each of the furnaces being provided withits own motor.

The shaft carrying the worm wheel 66 may also carry a sprocket driving achain' 72 which operates a circuit controlling d'elarge scale in Figure4. This circuit controlling device is formed with an endless inner slipring 76 and withl an outer slip ring 78 provided with .a break orinsulated portion 80. A single' brush .82 attached to the supply line 84is in constant engagement with the inner slip ring 76. The conductor 86leading-to the motor 70 is connected through a two-way ,one or the otherof the plungers 98 to connect the conductor 86 alternately with thebrush 94 and with the brush 96. The circuit is completed the slip ring 76 and the slip ring 78.

vIn the positions of the parts shown in Figure 4 the conductor 86 isconnected to the brush 96 whichis resting on the break or insulatedportion 80 and Vconsequently vthe motor 70 is not running. By depressingthe proper plunger 98 the conductor 86 is connected to the brush 94whereupon the motor, 70, Yand therefore the turret. '50. "will be drivenuntil the break .80 reaches the brush 94, thatl is, until the device 74has turned 180. If now the opposite plunger 98 is depressed to place thep conductor 86l once switch 88 to one of two conductors 90 4or 92 in com94 and 96, respec' by a connection 100 between are four idle carrierstwo of the carriers 102 the motor will again be driven until the device74 has turned through another arc of 180; It will be seen .thatthewmotor can be driven for twice this period, or until the device 74has turned through 360, by depressing both plungers` 98 one after theother in quick succession. In the positions shown" in Figure 4, forexample, when the h'rst plunger is depressed the device 74 will start toturn and the brush 96 `will ride' into e11- gagement withthe slip ring78 before the olther plunger 98 can be depressed to break t e the secondplunger 98 willthereafter throw the circuit back to the brush 96 againso that the circuit willnot be broken until the break 80 has travelled360 back to the brush 96. Thus it is possible to place axle sections ineach carrier of the `turret 50 when two men are operating the appara-tusor only, in every alternate carrier when only one man is operating it,or if preferred the one i'nanl may place themin each 'carrier and letthem remainin the furnace twice as long as when there' arev two men.

Each turret 50 carries a plurality of angularly spaced carriers l102"for the shafts these carriers being spaced apart at such an angle thatthe turret is advanced a distance equa-l to an advance of onecarriereach time the switch 88 is operated. Each turret shown in the drawingshas, 64 carriers. Each. carrier comprises suitable supports 104vcarrying .a conicalfguide or centering device 105 having a centA alopening through which the shaft S'passes', so that the shafts are atail-,times maintained in a truly vertical position and there is vnotendency for them to warp or otherwise change their shape, as when theyare treated in a hori-v zontal position.

Each of the furnaces is provided with adj agent charging danddischarging openings 106 and 108 respectively, ing spaced apart to beimmediately above In the arrangement shown, there between the twoopenings, so the furnace has a capacity of sixty shafts. Each pair ofopenings 106 and,108 is normally closed by a cover 110 containingrefractory material 112 and movable on is at rest.

a metal track 114 on rollers 1.16. The cover;

110 is normally held in aposition to cover bothiopenings 106 and 108 asshown on the furnace 12 in Figure 1 by opposed counter weights 118 and120. At the time the cover 110 is in this central position the counterweights-118 and 120 rest on cylindrical brackets 122 supported on thesides of the furnace. If the cover is moved in either direct-ion, theopposite counter Weight' wilf be lifted from itsbracket and will returnthe cover to its central position as soon as permitted.l ThecounterWeights are concurrent again, while the depression off these Aopemngsbewhen the turret 50- Vneet-ed to the cover lby cables or chains'124passing over pulleys 125.

Each cover 110 is connected at its opp siteends to cables Each cable 126pases over a pair of pulleys or chains 126 and 128. I

130 and is connected to one end of a conf necting rod 132 which assesthrough packings in opposite ends of The opposite end of the connectingrod 132 is connected to thecable 128 which is guided by a pair ofpulleys 136. Each connecting rod 132 carries a-double acting piston 138an air cylinder the. charging opening 106; and after deposit ng a shaftin the furnace through this opening, he can then lstep on the furtherpedal-to' open the dischargingopening 108; while after he removes thisopening and releases the corresponding` pedal t-he cover willautomatically be returned to its neiltral positioncovering both openingsby one or counter weights 11.8 or 120. It will also be vseen that -assoon as he has'done this h e may the shaft through t the other ofthe twodepress one or both of the plungers 98 ofI the switch 88 to cause theturret 50 to advance far enough to be ready for him the nextvtime hecomes round.

The quenching' tanta- The quenching tank l14 is arranged to receive thehot shafts from the hardening furnace 10 and prepare th'emA forinsertion in the drawing furnace 12, and to this end itis kept full ol?clear water at a constant temperature of substantially 190 F. `Thequenchingv tank comprises acylindrical water reservoir or tank proper inwhich is arranged aturret comprising a central shaft 152 carrying upperand lower arms 154 and 156 on which are arranged shaft carriers 157,each of which consists of a tubular sheet -metal guide 158 flor thewater and a conical lower support 16,0 for the shaft and an upper.conical support or guide 162 for centering the shaft and hold-f toprovide for Auniform ling it in -a truly vertical position In order.

cooling' of the shafts,

each ofthe supports and a162 is formed with water passages 164,arranged'at such an anglelas to give the entering water a clr-'cumferential' or centrifugal motion as' it passes through the tubularmember 158 to thev outlet'166 of the tank, and if desired a helicalsheet metal Water guide (not shown) may beprovided. Theabove describedturret is provided with six stations spaced 60 apart, and 1the lower'arms 156 are provided with radial Water passages 168 communicating withan axial passage 170 formed'in the shaft 152 or in a second shaftsecured to the shaft 152 andA forming a continuation thereof. Thepassage 170 receives a continuous supply of water from a pipe 172through which Water is constantly forced by a motor driven pump 174 froma supply tank 176. If desired, steam may be forced into the waterthrough a fitting 177 to agit-ate the water and lcause it to have a moreefficient cooling contact with the shafts S, and to cool the shafts moreuniformly, although this will not ordinarily be necessary if the pump174 has suiicient'capacity.

The turret inside of the tank-14 is advanced periodically, as theoperator inserts a hot shaft and removes a cool one, by a large gearv178 driven by a small gear 180 on a vertical shaft arranged to beconnected by form, toa short shaftl 186 in alinement therewith. Theshaft 186 is constantly driven by bevel gears 188 and ,190 from a crossvshaft 192 driven by suitable reduction wearing from a motor 194. The onerevolution clutch 184 is arranged to be operated by depression of aplunger 196 (Figure 1), which is arranged in a con- .venient positionadjacent the path of the operator as he moves 'from the quenching tankv14 to the furnace 12. inserted intok and removed from the quenchingtank. 14 lthrough adjacent tunnels 198, which are shown as beingconstantly open, this being permissible without undue loss, since thewater in the tank is not quite boiling.

The water in the quenching tank 14 and in the supply tank 176 ismaintained at a constant temperature by either adding cold water througha supply pipe 200 or steam through a supply pipe 202 arranged to dis--charge throu h openings in a longitudinally arranged fee pipe 204 insideof the supply tank 17 6. Thevaddition of cold Water is conare operatedby trolled by a valve 206 and the addition of steam is controlled-by avalve 208, each of these valves being operated by one of two compressed.air cylinders and pistons 210. One of the c/yli ders and pistons 210 isarranged to open its ,valve when\the compressed air is admitted and theother yone is arranged to close its valve when the com'- pressed air isadmitted, and' both of them air from a conduit 212 connected to lasupply conduit 214 through an air valve'A 216 `controlled by a Powerstype thermostat 218 in the supply tank 176. n the arrangement shown, anair gage 220 shows the pressure in the) supplyl line 214 and thepressure in the on a gage 222. When the water in the tank 176 is at thedesired constant'temperature both of the valves 208 and 206 are closed.`

a one revolution clutch 184 of any desired' The shafts ared conduit 212is shown If the water drops slightlyv in temperature,

the thermostat 218 operates the air valve v216 to open the valve 208 toadmit more steam;

when, on the other hand, the temperature lvided through which excesswater returning to the supply tank 176 from the quenching tank 114through the pipe 166 may run off.

The tmret- 16.-The turret 16 comprises upper and lower cross armscarried by a hollow central shaft 230 arranged to be moved by a radiall-extending armthe turret is to be riven by power, arm 231 may control acone clutch 232 operated by a gear/234 constantly driven.by a small gear236 on a vertical shaft 238 driven by bevel gears 240 from shaft 192.The cone clutch 282 is normally held in its disengaged osi.- tion bysprings 242 and is engaged to rive the turret onl as long as theoperator bears down on the andle 231, which is yarranged conveniently athis side as he follows the 'turret 16 around the platform 24.

At each end of the turret 1s anvair cylinder 246in which `is arranged adouble acting piston carrying a connecting rod 248 arranged to raise andlower the shafts S. Air is admitted to the bottom ortop of the cylinder246 through air conduits 250 controlled by a two-wa valve 252 op 254arrange in a convenient position, just above theoperators head. Airis..- supplied from connections 255 through the hollow shaft 230. Eachshaft is arranged to be grasped by novel tongs or a pair of jaws 256,further described3 below, supported at vthe bott-om of the connectingrod 248 and which are opened and closed by a piston and cylinder 258 opassing through flexible con uits 260 from the conduit 259, andcontrolled by a valve" 262 arranged to be opened and closed by theoperators finger engaging a finger piece 264, l

as he turns the lever 254 .u and down to control the raising and lowermof the tongs. Valve 262 is so arranged that t ereis aconstant lightpressure on the left of the piston (Figure 5) to serve the same generalpurpose as a return spring, while at the proper times the full pressureon piston closes the jaws firmly.

water is occasionally being erated by Ja lever vand which are erated byair- Y* the head( of the The power cylinder described above piv- 'Iotally mounted on the right hand jaw mem-k ber, and the piston ispositively connected to the left hand. jaw member by a pair ofconnecting rods 274 straddlingthe rod 248. In order to make sure thatthe jaws open and close equally, and to assist in opening and closingthem, they carry respectively `pairs of plates containingoppositely-inclined cam slots 276 and 278, all four of which slots em-1,697,820 l S brace pins 280 on links 282carried by ablock dle 231, ifthe turret is' power-driven, orI 284 secured, by a setscrew'orotherwise, to pushes on the handle himself, to causeA the .1

' rod 248. The jaws, which are pivotally conturret to turn incounterclockwise direction nected at 286, contain semi-sleeve lugs-288(Figure 1) until the 'shaft S is immediatel engaging the top of acompression spring 290 above the charging opening 106 of the hang 70confined between the lugs and a sto 292 on ening furnace, whereupon theoperator steps rod 248. The bottom parts of. the Jaws lare on the pedal146 tomove the cover 110 v beveled or conical, as shown at 2,94, toguide from above the opening 106, and manipuf them over the end of ashaft which is to be lates the tongs 256 to'lower the shaft into pickedup. one of the carriers 102 of the turret of the I6 Normally the jaws256 are held in open hardening furnace and release it there. He positionby the constant light pressure actthen raises the jaws 256 outiof thefurnace, ingFupon the left-of the piston 258 as shown steps on the pedal.148 to uncover the dis,- in igure 5. This pressure operates to drawcharging .opening 108, through which he the upper ends of thetongstogether, the removes a hardened shaft which has made inclination of theslots 276 and 278 causing the circuit of the furnace 10 in. the turret acomponent of this pressure, to act upon 50. As the operator leaves thefurnace 10 the ins 280, which are relatively fixed, to he dvepresses oneof the plungers98 of the lift e tongs upwardly on the rod 248. 'Thisswitch 88 to cause the turret 50`to be turned y lifting action isassisted bythe spring 290 ready for the next operation, while at the 85and may be further assisted by resting the same time the counter 'weight120 pulls the `lower ends of the ltongs upon a support. cover 110 backover the opening 108 into its With the jaws open, pins 280 occupy theneutral position. The operator next stops lower ends of the slots 276and 278. When the turret above the'quenching tank 14, dcthetongs havebeen inserted over the head positing in one of .the holders 158 the hot90 of the axle S, as shown in Figure 5, pressure hardened shaft which hehas justremoved is applied to the lright ,side of the piston 258 fromthe hardenin furnace, and removing overcoming the constant pressure onthe left through the other unnel 198 a shaftawhich side of the pistonand causing the upper hasv been around the quenching tank 14' and endsof the tongs to separate 'and ends to grip the axle, A part of the preS-the quenching tank .14 he steps on the plung-y sureon the piston isconverted' by the 1ner 196 to cause the turret in thequenching clinationofythe slots'- into a force urgingtank to be movedforward 60.

the tongs downwardly, on the rod 248, this The operator now depositsthe' cooled the lower been cooled thereby. 'As the operator leaves :95,

force beingaided by the weight ofthe tongs shaft, which he took from the.quenching 100 and of the axle which they grip and protank 14, in one ofthe carriers `102 of the ducing compression of the spring 290- turret 50of the drawing tank 12 through Shafts are Supplled the OperatOI by al1the charging opening 106, and immediately `assistant who places theminthe holder 266 thereafter removes throhghthe discharging- '(Figures 1and 5), having a tubular bottom Oening 108 a Shaft whleh has justze'om-106 P anda liaring or conical top to center` the @ted the circuit of thedrawing furnace, Jaws or tongs 256 onv the shaft. After th which lattershaft he. then. deposits in the shafts have been treated in thehardening water cooled holder 268 for removal by his furnace, thequenching tank, and the drawassistant. v in furnace the operator placesthem in a It will beseen that'the turret 16 is so ar- 110 cydricalholder 268` for removal by his ran ed that twov operators-canconveniently assistant. The holder 268 is kept full of wor at once, eachcarrying' the shafts water to a level determined by an overflow. throughthe same cycle but one ofthe, 0 pipe 270,to cool the shafts down to atemerators .being Constantly 180 behind t e perature at which'they canbe handled conother.4 Thatis, while the first operator is 116 veniently.l 4inserting a new shaft through. the openin vOperaMWh-'Ifile OpeItOIStands 011 the 106 'of the hardening furnace 10,1 the secon y platform24 beside one end of the turret 16, operator will be inserting aquenched shaft or'two operators may work at the same time, through theopenin 106 of the drawing furfone at each end of the turret 16. Theope-,nace 12; Whilethe rs1; Operator is'rem'oving 120 erator at theright ill Figur-@1 gIaSpS the a hardened shaft through the opening 108lever 254 which controls the raising and 10W of the furnace 10, thesecond operator will be ering of'the jaws 256, with his foreiingerremoving a drawn shaft through the opening adjacent the finger piece 260Which COIII'OIS 108 of the furnace 12; while the first operator rtheopening and closing of the Jaws. He is depositing' his'hardened shaftthrough one 125 first lowers the Jaws 256 and causes them to' ofthefunnels 198 in the uenching tank 14, close on a shaft S in the holder'266, as the second operator will e depositing his shown in .Figure 5,whereupon the jaws arei drawn shaft in the holder 268; and while raisedto the position shown in Figure 3.` the first operator is-removing `aquenched One of the operators now depresses the han? shaft throughthewsecond funnel 198, the 13 -spends in the furnaces,

. the same 'length of time .whetherl one or two operators are at work.As it does not make any particular difference how long a shaft stays inthe quenching tank 14, after it has been cooled off, it has not beenconsidered necessary to provide suchv a duplex starting .rlid stoppingmechanism for the-turret I1n ile one lllustrative embodimentl of theinvention has been described in det-ail, it is not the intention tolimit its scope to that fticular embodiment, or otherwise than by th'`terms of the appended claims. The term shaft, asvusedherein, is used asa convenient generic designation including analagousarticles such-as gunbarrels, etc;

We claim:

Wenching tank.

'1'. Shaft treating apparatus comprising,l

in combination, a lhardening furnace 1ncluding, a turret carrying asuccession of shafts, -a uenching tank, a' drawing fur- Anace inclu ng aturret carrying a succes- Sion ofshafts, and a conveyor for placing anuntreated shaft on a turret of the hardeningr furnace and removing ahardened shaft therefrom and placing it in the uenching tank, thenremoving a quenched s aft from-the. tank and placlng it on the turret ofthe 'drawing furnace, and for finally removing a drawn shaft from theturret of the drawing furnace.

'Shaft treating apparatus comprising, in'combiiiation, a hardeningfurnace constructed and arranged to hold a considerable numberofsha-fts; a quenching tank having a turret holding a plurality ofshafts, a rawing furnace constructed and arranged to hold a considerablenumber of shafts, and an operator-controlled conveyor for placing anuntreated shaft in the hardening furnace and removing a hardenedshafttherefrom, then lacing the hardened Vshaft on the tur- .ret ofjvthequenchingtank and removing a quenched shaft from the turret, and finallyp'licin'g the quenched shaft in the drawing rnace and removing a'drawnshaft there- 3. Shaft treating apparatus comprising, in combination, ahardening furnace, 'a quenchin tank, and a drawing furnace, eac/h ofsaid irnaces and the tank having-a v'charging vopening a'nd adischargingopen- `mg in itsV upper surface, means associated with eachof said furnaces and the tank to `moved through y.all of said chargingand may be in the furnaces y receive a shaft at the charging openin andto carry it to a position where it may e re the dischar ing opening,

disc arging openings being arranged substantially on the circumferenceof a circle, and an angularlymovable conveyor arranged -to be controlledby an operator and having ashaft carryin device movable along thecircumference o said circle.

4. Shaft treating apparatus com rising, iny combination, 'a turrethardening rnace, a turret quenching tank, a turret drawing furnace, allspaced angularly about a central axis, and a conveyor rotating aboutsaid central axis and arranged to be controlled by an operator, saidconveyor including power operated tongs for grasping a shaft and poweroperated meansfor raising and lowering the tongs.

5. Shaft treating apparatus comprising,

in combination a turret hardening furnace,

a turret quenching tank, a turret drawing furnace, anoperator-controlled conveyor movable in a circular path to transfershafts successively to the hardening furnace, the quenching tank, andthe drawing furnace, and vstopping and starting devices for thehardening furnace, the quenching tank, and the drawing furnace,respectively, arranged for convenient manipulation by the operator as heleaves the furnace or tank with which they are associated. 6. Thecombination of a heat treatingiurnace, a conveyor in said furnace forreceiving articles and carrying them in a continuous passage uenchingtank, c es through said tank, and operator con- -trolled devices'arranged t'o successively` load said first named conveyor with anuntreated article, place the treated article in said quenching tankconveyor and remove a cle therefrom. A

7. The combination as defined by claim 6, op effecting st 'p by stepmovement' of said hrough said furnace, a means for conveying artiremovea treated article therefrom,

quenched artierator controlled automatic devices for conveyors followingthe chargingand dis-v movement' of lla'i e through said furnace arotatable operator controlled conveying device for successivelysupplyingsaid furnace with untreated articles, removing treated articlestherefrom, placing the treated articles in the quenching tank andremoving the quenched articles therefrom.

10. The combination as defied by claim 9, and a drawing furnace a saiddevices and provided`-with a con,

passage through said furnace, saidlyiurnace sertion and removal f;articles,

ciated with eyorl 10 adapted to convey articles in a continuous beingprovided withl openings for the insaid openings being arranged lalo gthe same arc, and sa1d rotatable convey place quenched artic drawnarticles therefrom.

In testimony whereof we aix our signai being adapted to 15 es from saidtank `salcl drawing furnace conveyor and remove

